Dec. 1, 1864.] THE TECHNOLOGIST. 



LATELY INTRODUCED INTO EUROPE. 233 



that the worm fed on a tree resembling the Acacia. They tried the 

 leaves of the Ailanthus with success. From Piedmont it was intro- 

 duced into France, where the cultivation is now being pursued with 

 profit by independent persons, and also by others with assistance frojn 

 the Government. Though the silk of this insect is already used exten- 

 sively in France, it is only as spun silk — that is to say, carded like wool, 

 instead of being wound direct from the cocoon in a continuous thread, 

 as in the case of the mulberry silkworm. It was thought that, owing 

 to the structure of the cocoon, there was an insuperable difficulty in 

 doing so ; but there is reason to believe that some ingenious person has 

 lately discovered a method. Having watched the caterpillar in the 

 act of spinning, it does not appear to me that there is an impossibility 

 in obtaining a continuous thread. The difficulty arises from the threads 

 being laid more compactly than those of the mulberry silkworm, and 

 being cemented with a gum which we have not yet the secret of dissolv- 

 ing. To unwind the cocoon of the ordinary silkworm hot water is 

 sufficient. The cocoon of the Bombyx Cynthia is formed with an 

 elastic opening for the egress of the mature insect, and the supposi- 

 tion was that such an opening could not be made unless the threads 

 were cut ; but that, however, has already been proved to be a mistake. 

 From France the insect has been brought into England. The experi- 

 ment of its acclimatization was first tried by Lady Dorothy Nevill, at 

 Dangstein, near Petersfield, Hampshire. Her success was great, and 

 Lady Dorothy has recorded her experience in an interesting little 

 pamphlet, ' The Ailanthus Silkworm and the Ailanthus Tree.' 



In the autumn of 1863 (with a view to a similar experiment), some 

 Ailanthus were planted in the garden at Sheriff Hutton Park ; and in 

 the spring, two were set in pots in the greenhouse, as it seemed not 

 unlikely that the worms might do better on the living tree than on 

 sprays gathered and placed in water, which was the method usually 

 adopted. My wish of making the experiment (of how far the climate 

 of this part of England might suit these silkworms) becoming known to 

 Lady Dorothy Nevill, she very kindly made me a present of two dozen 

 newly-hatched worms, which reached Sheriff Hutton Park at half-past 

 seven o'clock on the morning of June 30th. They were first supplied 

 with fresh-gathered leaves, and, within two hours, twenty-three were 

 placed on one of the plants in the greenhouse ; the other worm, though 

 alive when the letter was opened, died shortly afterwards. In this situation 

 they throve satisfactorily, making changes, the description of which, by 

 Mons. F. Blain (in a little publication entitled ' Le ver a soie de 

 l'Ailante etson education en Anjou'), is so accurate, that I prefer using 

 it to attempting any one of my own. One little omission, however, I 

 must supply in its place. 



" The first age is the interval which passes from birth to the first 

 change ; in this age the young caterpillar is blackish, and its length is 

 about four millimetres (about one-sixth of an inch). The second age is 



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